refactor(animations): converge P1 motion durations to ≤300ms target

- 151 scripted + 1 manual duration fixes across 46 files
- framer entrance 0.5/0.6s -> 0.3s
- Tailwind hover -> duration-150, entrance -> duration-300
- preserve flip-clock/page-transition per semantic decision
- design-system.ts dead-code deferred
- P1 violations 156 -> 5; P0 remains 0; OK class 249 -> 400
- verified: tsc clean, eslint 0 errors
- verified: 130/130 jest suites, 1573 passed
- verified: visual regression 46/46 zero-pixel diff

Co-Authored-By: 阿睿 <workbuddy@tencent.com>

src/app/(marketing)/solutions/solutions-content-v3.tsx

@@ -129,7 +129,7 @@ function SolutionCard({ solution, index, products, featured = false }: { solutio
       initial={{ opacity: 0, y: 30 }}
       whileInView={{ opacity: 1, y: 0 }}
       viewport={{ once: true, margin: '-60px' }}
-      transition={{ duration: 0.6, delay: index * 0.08, ease: EASE_OUT }}
+      transition={{ duration: 0.3, delay: index * 0.08, ease: EASE_OUT }}
     >
       <StaticLink
         href={`/solutions/${solution.id}`}